The present invention relates to a device for protecting tools and workpieces from damage on a hydraulically or pneumatically operated stamping press and comprises an upper rigid pressing table supporting a cutting tool and a cooperating lower movable pressing table, and further includes a movable control element which responds either when the cutting tool contacts the material of the workpiece to be stamped or when a solid foreign body is situated between the material and a cutting tool. The device is further characterized in that the lower pressing table is so disposed in driving connection with a first switch and the movable control element with a second switch that the lower pressing table is arrested in its movement if the second switch is operated before the first switch.
Devices of this type are disclosed, for example, in Swiss Pat. No. 454,577 and German Utility Model No. 6,917,177. In the case of these known devices, one of the two pressing tables is formed in two parts in the stamping direction and is limitedly displaceable; the part supporting the cutting tools being kept apart from the other part by mechanical or pneumatic spring elements or by a hydraulic cushion until a force exceeding its own weight acts thereupon. In the latter case, the table part supported in the above-described manner, forms the movable element. Devices of this type have proved efficient in operation. However, they are subject to the disadvantage that the two-part configuration of the pressing table results in very high production costs. In addition, it is not possible to subsequently add such a device to an existing press without considerable expenditure.